Data Structures and Algorithms (3) - Joseph Problem, Recursion, Tower of Hanoi

package com.example.demo;

import java.util.ArrayList;
import java.util.List;

/**
 *
 * <P>Description: Joseph Problem</P>
 * @ClassName: YueSefu
 * @author Feng Hao on April 24, 2018 at 10:38:49 AM
 * @see TODO
  */ 
public  class YueSefu {
    
       public static void yuesefu(int totalNum, int countNum) {  
                  // 初始化人数  
                  List<Integer> start = new ArrayList<Integer>();  
                  for (int i = 1; i <= totalNum; i++) {  
                      start.add(i);  
                  }  
                  // count from the Kth   
                  int k = 0 ;  
                   while (start.size() >0 ) {  
                      k = k + countNum;  
                       // The index position of the mth person   
                      k = k % (start.size()) - 1 ;  
                      System.out.println(String.format( "k %s size %s" , k,start.size()));
                      // Determine whether the end of the queue is   reached 
                      if (k < 0 ) {  
                          System.out.println(start.get(start.size()-1));  
                          start.remove(start.size() - 1);  
                          k = 0;  
                      } else {  
                          System.out.println(start.get(k));  
                          start.remove(k);  
                      }  
                  }  
              }  

    public static void main(String[] args) {
        YueSefu.yuesefu(41, 3);
//        int a=3%1;
//        System.out.println(a);
    }

}

package com.example.demo;

import org.junit.Test;

/**
 *
 * <P>Description: recursive related code</P>
 * @ClassName: DiGui
 * @author Feng Hao on April 27, 2018 at 2:10:05 pm
 *
 *
 * Divide and conquer algorithm -- merge sort
 * / 
public  class DiGui {
    
    
    public long[] array;
    
    
    /**
     *
     * <p>Title: threeJiaoHanShu</p>
     * <p>Description: trigonometric functions</p>
     * @author Feng Hao on April 27, 2018 at 2:11:52 pm
     *
     * Description of trigonometric functions
     * 1 3 6 10 15 21 28
     * 1 2 3 4  5  6  7
     *
     * Query the value of the nth item, and check the data law to know that the value of n=n+n-1+n-2...1
     */
    @org.junit.Test
    public void threeJiaoHanShu() {
        int three = three(3);
        System.out.println(three);
    }

    public int three(int n) {
        System.out.println(n);
        // Explicit recursive base case 
        if (n == 1 ) {
             return 1 ;
        }else {
            return n+three(n-1);
        }
    }
    
    
    /**
     * i! factorial
     * 2！ 1*2
     * 3！ 1*2*3
     * 4！ 1*2*3*4
     * <p>Title: jiecheng</p>
     * <p>Description: factorial</p>
     * @author Feng Hao April 27, 2018 at 2:37:26 pm
      */
    @org.junit.Test
    public  void jiecheng() {
         int jie = jie(4 );
        System.out.println(jie);
    }
    
    public  int jie ( int i) {
         if (i == 1 ) {
             return 1 ;
        }else {
            return i * jie(i-1);
        }
    }
    
    
    /**
     *
     * <p>Title: twoFind</p>
     * <p>Description: binary search method</p>
     * @author Feng Hao April 27, 2018 at 2:55:08 PM
      */
    @org.junit.Test
    public void twoFind() {
        
        this.array= new long[] {1,2,4,6,8,9};
        long find = find(4, array.length, 0);
        System.out.println(find);
    }
    
    public long find(long key,int hight,int low) {
        int curIn=(low+hight)/2;
        
        if(array[curIn]==key) {
            return curIn;
        }else if(low>hight) {
            return array.length;
        }else {
            if(key<array[curIn]) {
                return find(key,curIn-1,low);
            }else {
                return find(key,hight,curIn+1);
            }
        }
    }
    
    
    /**
     *
     * <p>Title: hannuota</p>
     * <p>Description: Tower of Hanoi</p>
     * @author Feng Hao on April 27, 2018 at 3:52:21 PM
     *
     *Move the plate
     *     A    B    C
     *     3
     * first move n-1 in A to B
     * Then move the nth in A to C
     * Then move B in C to C    
     */
    @Test
    public  void hannuota() {
        moveTower(3, "A", "B", "C");
    }
    
    public void moveTower(int n,String from,String inner,String to) {
        if(n == 1) {
            System.out.println("Disk 1 from "+from+" to "+ to);
        }else {
            moveTower(n-1, from, to, inner);
            System.out.println("Disk "+n+" from "+from+" to "+ to);
            moveTower(n-1, inner, from, to);
        }
    }
    
    
}